Anti-skid roof underlayment

ABSTRACT

Anti-skid roof underlayment and methods of making are provided. A first layer is applied to a second layer to at least partially melt the second layer. The first layer and the second layer are embossed and laminated to a substrate, where the first layer and the second layer form an embossed layer on the substrate. The embossed layer has an anti-skid surface thereon.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 61/760,705, filed on Feb. 5, 2013. The entire disclosure of theabove application is incorporated herein by reference.

FIELD

The present technology relates to a roof underlayment with an embossedanti-skid surface for improved working or walking traction duringinstallation of the underlayment in various environmental conditions.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

In both residential and commercial roofing applications, a roofingmaterial is used to provide a weather and water protection barrier.Various roofing materials include composite shingles, metal panels orshingles, concrete or clay tiles, wood shakes, slate, concrete and claytile, and the like. In certain circumstances, water can penetrate theroofing material due to a primary roofing material design, installationpractices, or an accidental breach of the primary roofing material. Toprotect the building interior in these circumstances, a layer called aroofing underlayment can be provided beneath the layer of roofingmaterial. The roofing underlayment acts as a water and a moisturebarrier.

Underlayment can be affixed to a roofing surface, for example, by use ofvarious fasteners such as nails, staples, and the like, or through useof an adhesive. The underlayment can be substantially impermeable tomoisture. Additionally, it is desirable for the underlayment to havehigh tensile and tear strengths to reduce the likelihood of tearingduring installation and exposure to high winds. Underlayment canpreferably be light in weight to facilitate ease of transport andapplication, and should be able to withstand prolonged exposure tosunlight, air, and water.

Base sheet underlayment for various roof applications include tar paperfelt materials. Although widely used, these felt materials areassociated with numerous drawbacks that can diminish the integrity ofthe roof system. For example, felt absorbs moisture causing physicalexpansion where the material will buckle and wrinkle. Water can contactfelt during installation due to weather exposure and felt can alsoabsorb water after installation, where moisture from inside thestructure is generated from various sources, such as cooking, showers,industrial processes, etc. The buckling and wrinkling condition causesfelt to load up on any fasteners employed, causing tears or elongationof the felt at the fastener, which can compromise the integrity of theroof system. Felt containing moisture can also support growth of moldand fungus. What is more, felt has no natural protection from UV lightand can deteriorate when left exposed to direct solar radiation.

Polymeric roof underlayment materials, such as various polyolefinmaterials, are available that provide a significant improvement overstandard felts. Such synthetic polyolefin materials offer optimum levelsof tensile strength, light weight, and improved handlingcharacteristics. Typically a woven or non-woven polyolefin material iscoated on either one or both sides with a polymer coating. The polymercomposition of the woven material and coating are normally a variationor combination of polyethylene or polypropylene. These polyolefinmaterials provide several benefits in that they are inert and do notabsorb moisture or breakdown when exposed to harsh outdoor elements orchemicals. They can be resistant to rot and can have greatly improved UVresistance in comparison to felt.

A limitation of polyolefin roof underlayments is that these materialscan be very slippery in both wet and dry conditions. Installation of theunderlayment and the subsequent roofing material can therefore beproblematic as workers may need to walk across or work upon thepolyolefin material. This decreases the commercial attractiveness ofsuch materials for high pitch roof applications or in climatescharacterized by wet or humid conditions. Accordingly, it would bedesirable to provide a way to form a polymeric roofing underlayment thatalso provides anti-skid or enhanced friction properties.

SUMMARY

The present technology includes systems, processes, articles ofmanufacture, and compositions that relate to a roof underlayment havinga unique anti-skid surface that provides more traction and an improvedworking or walking surface during installation under variousenvironmental conditions.

Anti-skid roof underlayment and methods of making are provided. A firstlayer can be applied to a second layer to at least partially melt thesecond layer. The second layer includes a non-woven material having anarea density of less than about 25 grams per square meter. The firstlayer and the second layer can be embossed and laminated to a substrate,where the first layer and the second layer form an embossed layer on thesubstrate. The embossed layer has an anti-skid surface thereon.

In various embodiments, application of the first layer to the secondlayer can be performed before the embossing and laminating, orapplication of the first layer to the second layer can be performedsubstantially simultaneously with the embossing and laminating step. Theembossing can include contacting the second layer with a roller having atexture on a surface thereof, the texture imparting an inverse textureonto a surface of the second layer to form the anti-skid surface. Theroller can include a cooling means to remove heat from the embossedlayer. The embossing can also include contacting the substrate with apressure roller, where the roller and pressure roller define a nipconfigured to emboss and laminate the first layer, second layer, and thesubstrate. The anti-skid surface can include features having one of aheight and a depth of about 0.1 millimeters to about 1 millimeter.

In some embodiments, another first layer can be applied to anothersecond layer to at least partially melt the another second layer. Inthis case, the embossing and laminating step includes embossing andlaminating the first layers and second layers to the substrate, with oneof the first layers and one of the second layers forming an embossedlayer and the other of the first layers and the other of the secondlayers forming another embossed layer. The substrate is disposedintermediate to the embossed layers. Each embossed layer has ananti-skid surface thereon. The embossing can also include contactingeach of the second layers with a roller, where each roller has a textureon a surface thereof. The texture imparts an inverse texture onto asurface of the second layer to form the anti-skid surface. The rollersdefine a nip configured to emboss and laminate the first layers, secondlayers, and the substrate. In this way, the anti-skid roof underlaymentincludes a second embossed layer laminated to the substrate layer, wherethe second embossed layer has a second anti-skid surface thereon and thesubstrate layer is disposed intermediate to the embossed layers.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of an embodiment of an embossing roller foruse in making an anti-skid roof underlayment.

FIG. 2 is a perspective view of a portion of an embodiment of a roofunderlayment with an anti-skid surface.

FIG. 3 is a perspective view of a portion of another embodiment a roofunderlayment with an anti-skid surface.

FIG. 4 is a side elevational view of an embodiment of a process formaking a roof underlayment.

FIG. 5 is a side elevational view of an embodiment of another processfor making a roof underlayment.

FIG. 6 is a side elevational view of an embodiment of yet anotherprocess for making a roof underlayment.

DETAILED DESCRIPTION

The following description of technology is merely exemplary in nature ofthe subject matter, manufacture and use of one or more inventions, andis not intended to limit the scope, application, or uses of any specificinvention claimed in this application or in such other applications asmay be filed claiming priority to this application, or patents issuingtherefrom. Regarding the methods disclosed, the order of the stepspresented is exemplary in nature, and thus, the order of the steps canbe different in various embodiments. Except where otherwise expresslyindicated, all numerical quantities in this description are to beunderstood as modified by the word “about” in describing the broadestscope of the technology.

As illustrated in FIGS. 1-6, the present technology is drawn to methodsand means for making a roof underlayment 10 having an anti-skid surfaceand products formed thereby. The underlayment 10 can be a reinforcedroof underlayment configured to replace traditional asphalt saturatedfelt paper that is used on top of a wood roof deck, roof trusses orframe, and under roof coverings such as shingles, tile, metal, wood,concrete or clay tile, or other exterior cladding materials. In thisway, the roof underlayment 10 acts as a secondary weather resistivebarrier to protect the underlying structure.

Referring to FIG. 1, a roller 12 used for forming an anti-skid orenhanced friction surface of the underlayment 10 is illustrated. Theroller 12 is substantially cylindrical and includes a surface 14configured for embossing the underlayment 10 to form the anti-skidsurface. The surface 14 of the roller 12 includes a texture 16 formed bya plurality of features that are raised and/or sunken with respect tothe remainder of the surface 14 of the roller 12. For example, thetexture 16 can include a plurality of protrusions from the surface 14 ofthe roller 12, a plurality of depressions in the surface 14 of theroller 12, or both.

The texture 16 for forming the embossment on the underlayment 10 can beof varying heights or depths or can be substantially the same height ordepth. Examples of heights and depths of the texture 16 include between0.01 millimeters to 10 millimeters, between 0.1 millimeters to 1millimeter, and between 0.1 millimeters to 0.5 millimeters. Otherexamples include where the texture 16 has a substantially constantheight or depth of about 0.1 millimeters, about 0.5 millimeters, orabout 1 millimeter. However, it is understood that the height and/ordepth of the texture 16 can be tailored to provide a desired embossmenton the underlayment, where certain materials may be more or lesssensitive to forming an impression from contact with the roller 12.

The texture 16 can be disposed on the surface 14 of the roller 12randomly or can be configured as a uniform or repeated pattern. Asillustrated in FIG. 1, the texture 16 is disposed on the surface 14 ofthe roller 12 in a random configuration. Where the texture 16 isdisposed as an array of uniform or repeating configurations, examplesinclude straight lines, a cross-hatch pattern, a chevron pattern, achecked pattern, or any other pattern as desired.

The texture 16 can include raised and/or sunken features that areadjacent each other or spaced apart from each other providing variousfeature densities. Examples include where the texture 16 includesbetween 1 feature to 100 features per square centimeter of the surface14 of the roller 12. Other examples include where there are about 10features per square centimeter, 20 features per square centimeter, orabout 50 features per square centimeter of the surface 14 of the roller12. Additionally, the features of the texture 16 can have the same shapeor can have varying shapes such as square, triangular, circular, ovular,obround, rectangular, or any other shape configured to form an anti-skidsurface. In certain embodiments, the texture 16 can include a randommixture of raised and sunken features that forms a grainy pattern 14 onthe roller 12. Such textures 16 can include a grainy pattern similar tosandpaper.

The roller 12 can be configured as or with a cooling means to removeheat from underlayment 10 that is being embossed therewith. In certainembodiments, the roller 12 can include a heat conductive material thatoperates as a heat sink to cool the underlayment 10. For example, theroller 12 can be referred to as a chilling roller 12, where at least thesurface 14 and/or the texture 16 of the roller 12 can be made of metalso that the roller 12 is configured to both emboss and to cool theunderlayment 10 during fabrication thereof. However, the roller 12 cancool the underlayment 10 by any cooling means as desired. For example,the roller 12 can be actively cooled by fans at opposing ends thereof orinclude an interior chiller or coolant flowing therethrough. It is alsounderstood that the roller 12 can be formed by any metal material or anyother material such as rubber, plastic, or ceramic, for example. Theroller 12 can also include a protective layer or coating such as a metalcoating (e.g., chrome or zinc plating), rubber coating, siliconecoating, thermal-plastic coating, or thermal sprayed coating.

As shown in FIG. 2, the underlayment 10 can be a single-sided anti-skidunderlayment includes a substrate layer 18 and an embossed layer 20. Insome embodiments, the substrate layer 18 and/or the embossed layer 20can be a material that is vapor permeable, while in other embodimentsthe substrate layer 18 and/or the embossed layer 20 can be vaporimpermeable. Examples of the substrate layer 18 include a woven ornon-woven substrate, scrim, mesh, or base fabric, including variouswoven or non-woven polyolefin materials. In embodiments where thesubstrate layer 18 and/or the embossed layer 20 is vapor impermeable,examples include any suitable impermeable sheet, such as films or sheetsof polyolefins, including polypropylene, polyethylene or polyvinylchloride or other impermeable weather resistant building papers. Inembodiments where the substrate layer 18 and/or the embossed layer 20 isvapor permeable, examples include any suitable vapor permeable sheetthat is water resistant. Vapor permeable flexible sheets may be anysuitable breathable sheet material made of spun bonded synthetic fiberssuch as polyethylene, polypropylene or polyester fibers, sheets of spunbonded-melt blown-spun bonded polymer fibers (or other non-wovenfabricated products), perforated polymer films, woven slit film,microporous film laminates, and building papers.

The substrate layer 18 can comprise a commercial roof underlayment orhouse wrap. In certain embodiments, the substrate layer 18 can comprisea product such as RoofLiner or Tyvek™ HomeWrap, available from DuPont(Wilmington, Del.), Typar™ HouseWrap, available from BBA Fiberweb (OldHickory, Tenn.), or equivalents thereof. In some embodiments, thesubstrate layer 18 can include an insulating and/or reinforcingmaterial, such as fiberglass, or may be combined with or coupled to aninsulating and/or reinforcing material, or the substrate layer 18 can beused and/or installed in conjunction with an insulating and/orreinforcing material.

The embossed layer 20 includes a first layer 22 and a second layer 24.The first layer 22 can include one or more of a polyolefin film, a hotmelt plastic film, an adhesive film or tie layer, and can be formed froma melted resin curtain. In certain embodiments, the first layer 22 isconfigured to at least partially melt the second layer 24 during amanufacturing process, as further described hereinbelow, and provideadhesion between the embossed layer 20 and the substrate layer 18. Wherethe first layer 22 at least partially melts the second layer 24, thefirst layer 22 and second layer 24 can intermingle and allow for amixing of their respective materials, such as fibers or polymericmaterials, therebetween. The second layer 24 can be a non-woven materialthat can be imparted with an anti-skid property, for example, exhibitingincreased friction or traction upon being embossed.

The second layer 24 can include a thin non-woven material having an areadensity of less than about 25 grams per square meter. Examples ofmaterials useful as the second layer 24 include spun bonded or needlepunched polyolefin or polymeric type non-woven materials. As such, therelatively light weight (i.e., less than about 25 g/m²) of the secondlayer 24 makes at least a portion of the second layer 24 relatively easyto melt upon contact with the first layer 22. In fact, in someembodiments, a majority of the second layer 24 can melt and intimatelymix with the first layer 22, allowing a limited amount of the secondlayer 24 to remain. In certain cases, a portion of the non-wovenmaterial of the second layer 24 may appear to “burn-off” followingcontact with the first layer 22. The remaining amount of the non-wovenmaterial of the second layer 24 is thereby made resistant to fraying andpiling. This is not the case with non-woven material having an areadensity of greater than 25 grams per square meter. Such heavier weightnon-woven materials result in a second layer that can exhibit fraying orpiling, where such defects can increase the slipperiness of second layer24 and are antithetical to the formation of an anti-skid surfacethereon. Thus, it has been found that use of a non-woven material ofless than about 25 g/m² in area density can surprisingly reduce orprevent any fraying or pilling that would contravene the effect ofembossing an anti-skid surface thereon.

In certain embodiments, the substrate layer 18 and/or the embossed layer20 can include other materials such as a rolled-on or sprayed-on liquidthat dries or cures as a film directly on another material, such asanother film or sheet material or a building material or component suchas sheathing material. In addition, the substrate layer 18 and/or theembossed layer 20 can include one or more of a woven material, anon-woven material, a dry-laid non-woven material, a wet-laid non-wovenmaterial, a hybrid non-woven material, a polymer-laid non-wovenmaterial, a spun-bonded non-woven material, a flash-spun non-wovenmaterial, or the like. Furthermore, natural materials, such as celluloseand other plant derived products, used alone or in conjunction with thevarious synthetic materials described herein can be included.

The embossed layer 20 includes a surface 26 having an inverse texture 28formed thereon. The inverse texture 28 at least partially corresponds tothe inverse of the texture 16 on the surface 14 of the roller 12. Forexample, the inverse texture 28 can be a substantial complement of thetexture 16 on the surface 14 of the roller 12. In this manner, theinverse texture 28 can exhibit a plurality of features that are raisedand/or sunken with respect to the remainder of the surface 26 of theembossed layer 20.

With reference to the figures, the embossed layer 20 is illustrated withthe first layer 22 as a distinct layer from the second layer 24.However, in application, the first layer 22 and the second layer 24 canat least partially form an integral bond and/or intermingle during themanufacturing process, such that the first layer 22 and the second layer24 may become at least partially amalgamated, especially at theinterface thereof. Heat can be applied to the first layer 22 and thesecond layer 24 or a melted or partially melted first layer 22 canpartially melt the second layer 24 upon contact, for example. The firstlayer 22 may also at least partially form an integral bond and/orintermingle with the substrate layer 18, so that the first layer 22 andthe substrate layer 18 may become at least partially amalgamated,especially at the interface thereof. As described, the second layer 24can include a thin non-woven material having an area density of lessthan about 25 grams per square meter that is made resistant to frayingand pilling upon contact with the first layer 22 and partially melting.In various embodiments, the underlayment 10 can include any number offirst layers 22, second layers 24, and/or substrate layers 18, asdesired. In a non-limiting example, as shown in FIG. 2, the underlayment10 includes one embossed layer 20 formed of one first layer 22 and onesecond layer 24, along with one substrate layer 18.

In another non-limiting example, as shown in FIG. 3, the underlayment10′ can be a double-sided anti-skid underlayment including two embossinglayers 20′ and one substrate layer 18′. Structure similar to that shownin FIG. 2 are represented with the same reference numeral and a prime(′) symbol for clarity. In this embodiment, the substrate layer 18′ isdisposed intermediate the embossing layers 20′. According to thisembodiment, the underlayment 10′ includes inverse texture 28′ formed onthe surface 26′ of one of the embossing layers 20′ and on an opposingsurface 30 of the other of the embossing layers 20′. The inverse texture28′ formed on each of the surfaces 26′, 30 can be different, similar, oridentical, and/or one can have more aggressive raised and/or sunkenfeatures than the other. It is understood, the underlayment 10′ caninclude any number of first layers 22′, second layers 24′, and substratelayers 18′ as desired.

With reference now to FIG. 4, an embodiment of an embossing process 32to form the underlayment 10 is illustrated, where relative movement ofcomponents is indicated by block arrows. The embossing process 32includes the roller 12 cooperating with a pressure roller 34 to define anip that is configured to bond the substrate layer 18, the first layer22, and the second layer 24. The pressure roller 34 can be a rubberpressure nip roll, for example. However, the pressure roller 34 can beany roller formed of any material such as metal or plastic and caninclude coverings such as urethane or plastic. In a first step, thefirst layer 22 is heated, prior to or upstream in the embossing process32 from the roller 12, to a temperature and applied to the second layer24 to at least partially melt the second layer 24. For example, in thisstep, the first layer 22 can be a hot melt film or curtain formed from adie laid down on the second layer 24 to at least partially melt thesecond layer 24.

In a second step, the combined first layer 22 and the at least partiallymelted second layer 24 meet the substrate layer 18 and are pressed orlaminated between the roller 12 and the pressure roller 34 at the nip toform the underlayment 10. As the first layer 22, second layer 24, andthe substrate layer 18 are being pressed together between the roller 12and the pressure roller 34, the texture 16 of the roller 12 is embossedonto the surface 26 of the embossed layer 20 to form the inverse texture28. The embossed layer 20 is also bonded to the substrate 18 at thispoint, where the first layer 22 of the embossed layer 20 facilitatesadhesion of the embossed layer 20 to the substrate layer 18. The roller12 is configured to cool and at least partially solidify the embossedlayer 20 to substantially maintain the formation of the inverse texture28 and to militate against a warping of the underlayment 10 as it isbeing formed. The result of the embossed inverse texture 28 formed onthe surface 26 of the embossed layer 20 is a unique anti-skid surfacewhich provides the underlayment 10 with anti-skid properties and bettertraction and improves the working or walking surface thereon duringinstallation of roof coverings under various environmental conditions.

Referring now to FIG. 5, the embossing process 32 for forming theunderlayment 10 is illustrated according to another embodiment, whererelative movement of components is again indicated by block arrows. Inthis case, a one step process is employed wherein the first layer 22 isheated and applied as a hot curtain of extrusion coating or film, forexample, intermediate of the substrate layer 18 and the second layer 24while the substrate layer 18 and the second layer 24 are being pressedbetween the roller 12 and pressure roller 34. In this embodiment, thefirst layer 22, the second layer 24, and the substrate layer 18 arepressed through the nip in one step, in a substantially simultaneousfashion. As the substrate layer 18, first layer 22, and second layer 24are being pressed or laminated by the roller 12 and pressure roller 34,the texture 16 of the roller 12 is embossed onto the surface 26 of theembossed layer 20 to form the inverse texture 28. The inverse texture 28correspond to the texture 16 formed on the surface 14 of the roller 12.The first layer 22 of the embossed layer 20 facilitates adhesion of theembossed layer 20 to the substrate layer 18. The roller 12 is configuredto cool and at least partially solidify the embossed layer 20 tomaintain the formation of the inverse texture 28 and to militate againsta warping of the underlayment 10 as it is being formed. The result ofthe embossed inverse texture 28 formed on the surface 26 of the embossedlayer 20 is a unique anti-skid surface which provides the underlayment10 with anti-skid properties and better traction and improves theworking or walking surface thereon during installation of roof coveringsunder various environmental conditions.

With reference to FIG. 6, an embossing process 32′ for forming adouble-sided anti-skid underlayment 10′ having two embossing layers 20′is illustrated, where relative movement of components is indicated byblock arrows. Structure similar to that illustrated in FIGS. 4 and 5include the same reference numeral and a prime symbol (′) for clarity.The embossing process 32′ includes the roller 12′ cooperating with thepressure roller 34′ to bond the substrate layer 18′ to two embossedlayers 20′. According to this embodiment, the pressure roller 34′ isconfigured to operate in a substantially similar or identical fashion toroller 12′. That is, roller 34′ can be have the attributes as describedherein for roller 12. Briefly, pressure roller 34′ can be configured toemboss and to cool the underlayment 10′ during formation of theunderlayment 10′. The pressure roller 34′ further includes a texture 16′as described herein, for forming an inverse texture 28′ on the surface30 of the underlayment 10′. The texture 16′ on the pressure roller 34′can be different, substantially similar, or identical, and/or caninclude more or less aggressive raised and/or sunken features than thetexture 16 on the roller 12′.

In a first step, each of the first layers 22′ are heated, prior to orupstream in the embossing process 32′ from the roller 12′ and thepressure roller 34′, to a temperature and applied to each of the secondlayers 24′ to at least partially melt each of the second layers 24′. Forexample, in this step, the first layers 22′ can be a hot melt film orcurtain formed from a die laid down on each of the second layers 24′ toat least partially melt each of the second layers 24′.

In a second step, each of the first layers 22′, second layers 24′, andthe substrate layer 18′ meet at the roller 12′ and the pressure roller34′ and are pressed or laminated at the nip defined by the roller 12′and the pressure roller 34′ to bond each of the first layers 22′ andsecond layers 24′ to the substrate layer 18′ to form the underlayment10′. In this embodiment, the substrate layer 18′ is intermediate thefirst layers 22′ and the second layers 24′ in forming the embossedlayers 20′ and substrate layer 18′ upon being pressed or laminatedtogether. As the embossed layers 20′ and the substrate layer 18′ arebeing embossed, the texture 16′ of the roller 12′ forms an inversetexture 28′ on the surface 26′ of one of the embossed layers 20′, whichis a substantial complement of the texture 16′ formed on the surface 14′of the roller 12′. The texture 16′ of the pressure roller 34′ formsanother inverse texture 28′ on the surface 30 of the other one of theembossed layers 20′, which is a substantial complement of the texture16′ formed on the pressure roller 34′. The first layers 22′ of theembossing layers 20′ facilitate adhesion of the embossing layers 20′ tothe substrate layer 18′. The roller 12 and the pressure roller 34′ areconfigured to cool and at least partially solidify the embossing layers20′ to maintain the formation of the inverse textures 28′ and tomilitate against a warping of the underlayment 10′ as it is beingformed. The result of the inverse textures 28′ formed on the surfaces26′, 30 of the embossing layers 20′ is a unique anti-skid surface oneach side of the underlayment 10′ that gives the underlayment 10′ moretraction and provides an improved working or walking surface duringinstallation of roof coverings under various environmental conditions.In this manner, the underlayment 10′ can be installed in roofingapplications without concern to orientation or the various inversetextures 28′ can be configured to perform with certain surfaces. Forexample, one of the inverse textures 28′ can be tailored to provideanti-skid properties for workers to walk on during installation of aroof while the other inverse texture 28′ can be tailored to provideincreased friction against a particular building material upon which theunderlayment 10′ is installed.

As shown, FIG. 6 illustrates a two step process for forming thedouble-sided anti-skid underlayment 10′ with two embossing layers 20′,with similar aspects to those shown in FIG. 4. However, it is understoodthat the underlayment 10′ can be formed by a one step process, similarto that shown in FIG. 5, wherein the first layers 22′, the second layers24′, and the substrate layer 18′ are pressed through the nip in onestep, in a substantially simultaneous fashion.

In certain embodiments, the underlayment 10, 10′ formed by the embossingprocess 32, 32′ is a flexible sheet comprising one or more substratelayers 18, 18′ and one or more embossing layers 20, 20′. In someembodiments, the flexible sheet of underlayment 10, 10′ can be providedin an indefinite-length elongate web that is capable of being stored andshipped in a spirally wound roll. Other shapes and forms of the flexiblesheet include strips, perforated sheets, and precut sheets.

Various additives can be included or applied to the underlayment 10,10′. Examples include various colorants, heat stabilizers, waterproofingtreatments, strengthening laminates, antimicrobials, UV blockers andlight stabilizers, and flame retardants. The underlayment 10, 10′ can bealso be printed with signage, such as logos, installation instructions,and orientation indicia. In certain aspects the underlayment 10, 10′ caninclude suitable additives. The underlayment 10, 10′ can include aninsulating material, such as fiberglass, or may be combined with orcoupled to an insulating material, or the sheet can be used and/orinstalled in conjunction with an insulating material.

In application, the underlayment 10, 10′ is applied beneath a roofingmaterial such as composite shingles, metal panels or shingles, concreteor clay tiles, wood shakes, slate, concrete and clay tile, and the like.The underlayment 10, 10′ is positioned such that the inverse texture 28(or one of the inverse textures 28′) is facing upwards. The inversetexture 28, 28′ formed on at least one surface of the underlayment 10,10′ forms an enhanced friction surface thereon such that duringinstallation, the enhanced friction surface or anti-skid surfacemilitates against slipping and facilitates working or walking tractionduring installation of the underlayment 10, 10′ and roofing materials.Also, attachment or adhesion of the underlayment 10, 10′ to otherroofing materials can be enhanced.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms, and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail. Equivalent changes, modifications and variations ofsome embodiments, materials, compositions and methods can be made withinthe scope of the present technology, with substantially similar results.

What is claimed is:
 1. A method of making an anti-skid roof underlayment comprising: applying a first layer to a second layer to at least partially melt the second layer, wherein the second layer includes a non-woven material having an area density of less than about 25 grams per square meter; and embossing and laminating the first layer and the second layer to a substrate, the first layer and the second layer forming an embossed layer on the substrate, the embossed layer having an anti-skid surface thereon.
 2. The method of claim 1, wherein the first layer is heated prior to application to the second layer.
 3. The method of claim 1, wherein the applying step is performed before the embossing and laminating step.
 4. The method of claim 1, wherein the applying step is performed substantially simultaneously with the embossing and laminating step.
 5. The method of claim 1, wherein the embossing comprises contacting the second layer with a roller having a texture on a surface thereof, the texture imparting an inverse texture onto a surface of the second layer to form the anti-skid surface.
 6. The method of claim 5, wherein the roller comprises a cooling means to remove heat from the embossed layer.
 7. The method of claim 5, wherein the embossing comprises contacting the substrate with a pressure roller, where the roller and pressure roller define a nip configured to emboss and laminate the first layer, second layer, and the substrate.
 8. The method of claim 1, wherein the anti-skid surface comprises features having one of a height and a depth of about 0.1 millimeters to about 1 millimeter.
 9. The method of claim 1, wherein the first layer comprises one of a hot melt plastic film and a melted resin curtain and the substrate comprises a woven material.
 10. The method of claim 1, further comprising: applying another first layer to another second layer to at least partially melt the another second layer; wherein the embossing and laminating step includes embossing and laminating the first layers and second layers to the substrate, one of the first layers and one of the second layers forming an embossed layer, the other of the first layers and the other of the second layers forming another embossed layer, the substrate intermediate to the embossed layers, the embossed layers each having an anti-skid surface thereon.
 11. The method of claim 10, wherein the embossing comprises contacting each of the second layers with a roller, each roller having a texture on a surface thereof, the texture imparting an inverse texture onto a surface of the second layer to form the anti-skid surface, where the rollers define a nip configured to emboss and laminate the first layers, second layers, and the substrate.
 12. The method of claim 11, wherein the applying step is performed before the embossing and laminating step.
 13. The method of claim 11, wherein the applying step is performed substantially simultaneously with the embossing and laminating step.
 14. An anti-skid roof underlayment comprising: a substrate layer; and an embossed layer laminated to the substrate layer, the embossed layer including a first layer and a second layer, the first layer intermediate to the substrate layer and the second layer, the second layer including a non-woven material having an area density of less than about 25 grams per square meter, the second layer having an anti-skid surface thereon.
 15. The anti-skid roof underlayment of claim 14, wherein the substrate layer comprises a woven material and the first layer comprises one of a hot melt plastic film and a melted resin curtain.
 16. The anti-skid roof underlayment of claim 14, wherein the anti-skid surface comprises features having one of a height and a depth of about 0.1 millimeters to about 1 millimeter.
 17. The anti-skid roof underlayment of claim 14, further comprising a second embossed layer laminated to the substrate layer, the second embossed layer having a second anti-skid surface thereon, the substrate layer intermediate to the embossed layers.
 18. A method of using an anti-skid roof underlayment comprising: positioning an anti-skid roof underlayment on a roof, the anti-skid roof underlayment comprising a substrate layer and an embossed layer laminated to the substrate layer, the embossed layer including a first layer and a second layer, the first layer intermediate to the substrate layer and the second layer, the second layer including a non-woven material having an area density of less than about 25 grams per square meter, the second layer having an anti-skid surface thereon. 